ICB1FL02G Datasheet, PDF (32/37 Pages) Infineon Technologies AG – Smart Ballast Control IC for Fluorescent Lamp Ballasts

ICB1FL02G
Application Examples
Lamp voltage sense resistors R31, R32, R33:
The selected lamp type 54W-T5 has a typical run voltage of 167V peak. We decide to set the EOL-thresholds at
a level of 1,5 times the run voltage level (= 250,5V peak).
R31 + R32 + R33 = _{I---L-V---V-L----SE---E-O----O-L---L--} = -2-2-5--1-0--5--^,-_µ-5---A-V--- = 1165kΩ
Selected values: R31= 390k; R32= 390k; R33= 390k (=1170k).
Current source resistors R34, R35 for detection of high-side filament:
R34 + R35
=
-----------V-----I--N-----M------I--N--------------
ILVSSINKMAX
–
(R31
+
R32
+
R33)
=
-22--6-0---0_µ---V-A--- – (1170k)
=
6522 k Ω
Selected values: R34= 2,2M; R35= 2,2M;
Current limitation resistor R30 for floating bootstrap capacitor C14:
A factor of 2 is provided in order to keep current level significant below LSCS turn-off threshold.
R30
≥
---2----^â‹---V-----C----C-----O----N-----
VLSCSOVC
⋅
-R-----2---4----^â‹---R----2---5---
R24 + R25
=
2---1--⋅_{-,--1-6--4-V--V--- ⋅ 0-0--,-},_{--8-8--2-2----+-}⋅_---0-0--,_{-,--8-8--2-2-}
=
7, 18Ω
Selected value: R30= 10Ohm.
Low-side filament sense resistor R36:
For a single lamp ballast
Selected value: R36= 56k
R36 ≤ ^{V----I-R-R----E-E---S-S--C--3---1M---M---I--N-I---N--} = -2-1-7--^,-_,--5-0--5--_µ--V--A--- = 57, 4kΩ
R36
A
≥
V-----R----E-----S---C-----1---M------A-----X---
IRES3MAX
=
-1-1-5--^,-_,--6-1--5--_µ--V--A---
=
109, 3kΩ
Selected values in a topology with 2 lamps in parallel: R36A= 110k; R36B= 110k.
Low pass filter capacitor C19:
Capacitor C19 provides a low pass filter together with resistor R36 in order to suppress AC voltage drop at the
low-side filament. When we estimate an AC voltage of 10V peak-to-peak at low-side filament during run mode at
f_RUN= 40kHz, we need a suppression of at least a factor F_LP= 100 (-40dB).
C19 =
(^---2----⋅^---π^-----⋅^{-F--f-L2-R---P--U---–--N---1---}⋅^{---R----3---6---})^{- =}
2
(^---2----⋅^---π^-----⋅^{-1--4-0--0-0---k---H-–----z-1---}⋅^{---5---6----k---}) ^{= 7, 1nF}
Selected value for better ripple suppression: C19= 22nF.
Datasheet Version 1.2
32
February 2006